Atmospheric Infrared Sounder: Detector Noise Equivalent Delta Temperature (NEdT) Trend

The page presents the near-term and long-term noise characteristics (referenced to 250 K) of the 2,378 AIRS IR channels.

Updated: 20-Sep-2026 08:21:16

• Columns 1 and 2 show the Channel ID and its nominal Spectral Response Function centroid frequency (units of wavenumber).
• Column 3 reports the number of days in the near-term period when the channel NEdT levels exceeded its dynamically-calculated alert threshold.
• Columns 4 - 6 report the minimum, mean, and maximum NEdT values observed over the near-term time period.
• Columns 7 is a time history (every six-minute data granule) of NEdT values observed over the near-term time period.
• Columns 8 is a time history of daily summary statistics (min/mean/max) of NEdT values observed throughout the operational mission.

NOTES ABOUT THESE DATA:

• The NEdT value shown here is calculated from the NeN data field, which is provided as a single number per channel in each Level 1B six-minute granule data product.
• The SRF centroid frequency shown here is a nominal value. Please refer to the Level 1B data six-minute granule data product for a dynamically-calculated SRF centroid frequency.
• The NEdT range for a properly-functioning channel is between 0.0 and 1.0 K, but occasional excursions above 1.0 K are tolerated. Levels of 10.0 K or above denote a non-functioning channel.
• For the daily NEdT statistics shown here, the daily data set contained at least 30 of the expected 240 data granules per day.